Ground testers are devices used to measure the resistance of earth to a buried ground rod or electrode. Proper grounding is required by many industries and applications and grounding recommendations and practices exist from many organizations, such as NEC (National Electric Code), OSHA, ANSI, TIA (Telecommunications Industry Association), IEEE, as well as others.
Earth grounding is used to provide a connection from electronics and power to earth. Earth grounding provides protection for faults, lighting strikes, RFI, EMI, and other interference. Poor grounding can result in injury or death to people, animals, and plants. It can also result in damage, poor operation, or the failure of equipment and electronics to operate.